The students will make thier 100 days smarter hats when they arrive. I got the idea from The Chalk Box and I love it. They have to put 10 little stickers on 10 strips and count by 10's to 100.
One activity that I enjoy doing but did not get a picture of this year is when the students draw a picture of their face at 100 years old on paper and then we crinkle the paper up into a ball. When we open it up, it looks like they have wrinkles on their face. So cute!